Temporal Video Transcoding in Mobile Systems

This thesis approaches the problem of temporal video transcoding in wireless networks. The general aim is to investigate temporal transcoding for improving real-time video communication of multimedia services, by considering peculiar features of infrastructured and ad hoc wireless networks. We address the main issues of temporal transcoding, pointing out their characteristic problems and presenting our original proposals (motion vector composition algorithm and frame skipping policies). We focus on IEEE 802.11 vehicular networks, for presenting a temporal transcoding system able to improve real-time video communication, overcoming the typical network congestion and reducing late frames.